Mantic Effects Flex Pro Pll - UsedThis Synth pedal is in Excellent condition with little to no wear Mantic Effects' Flex Pro is an analog Phase Locked Loop, or PLL, synthesizer. On guitar, it is an almost uncontrollable element. Its learning curve may provide new sonic possibilities, which is the nice way of saying it will take your input, chew it up, spit it out and send you spiraling into the upside down that is error signal. Six onboard pots and two mini switches control effect